We don’t know when Robyn Regehr will be back, but we now know what’s keeping him out.

On Thursday, Kings head coach Darryl Sutter told reporters Regehr, who hasn’t played since Game 1 of the Anaheim series, is out with a knee injury and is still unable to take to the ice.

“Robyn’s not skating,” Sutter said, per NHL.com. “When Robyn’s ready to skate, he’ll skate. It’s a knee injury, and obviously he’ll make that decision. If he could play on one leg, he would. He showed it last year in the playoffs.

“If there’s a way to skate, he’d be playing.”

Regehr, 34, was hurt during a collision with Teemu Selanne 19 days ago. He was averaging over 17 minutes a night and was a key contributor for the Kings in their comeback against San Jose in the opening round, registering an assist in Game 6 while finishing plus-3 in Game 7.